Transcript PP - Bishops

Diversity of Organisms and
Classification
Classification



Taxonomy – sorts all living things into
groups.
We use way an organism is ‘built’ to
split into groups – organism with similar
‘body plan’ will be in same group
Scheme based on work by Linnaeus (
18th century)
Classification of Organisms
Kingdom
Phylum
Class
Order
Family
Genus
Species
Species



The smallest group of organisms classified
which can interbreed with each other to
produce fertile offspring
Scientific name : unique to species
Bionomial name- 2 parts
– Part 1 genus
– Part 2 something no other organism in genus can
have.

e.g. scientific name of human :
Homo sapiens
Keys – how to simplify classification


Keys – easy to follow representations of
classification systems
Most common- dichotomous keys
– TWO choices at every point – start with
one group and slowly divide until no further
choice
– Set out: branching or tabular
Five Kingdom System






Prokaryotes
Protoctista
Fungi
Plants
Animals
And Viruses?
Viruses




Non cellular – no membranes and
organelles missing
Made of organic substances like
proteins and fats
Contain DNA or RNA
Can reproduce inside another living
organism (parasitic)
Prokaryotes(Bacteria)



Unicellular,
microscopic
No membrane
bound nucleus
Some have no
chlorophyll
– Saprophytic or
parasitic
– Saprophytic: feed
on dead
substances
– Parasitic: obtain
nutrients from
living organisms
Protoctists



Unicellular or simple multicellular,
microscopic, diverse group, wide spread
in water
Nucleus surrounded by a membrane is
present = Eukaryotic
Autotrophic or heterotrophic
Fungi


Eukaryotic (cells have
nuclei)
Made up of hyphae
– Mycelium : a mass of
hyphae


No root, stem and leaf
No chlorophyll
– Saprophytic or
parasitic

Reproduce by forming
spores
Animals


Eukaryotic (cells have nuclei)
Divided into two groups according to the
presence or absence of backbone:
– Invertebrates : without backbone
– Vertebrates : with backbone
Invertebrates
Invertebrates: Phylum Athropoda
Myriapoda
Class: Insecta
Crustacea
Insecta
Arachnida
Invertebrates
Mollusca
Echinodermata
Vertebrates

Divided into 5 groups:
– Fish
– Amphibians
– Reptiles
– Birds
– Mammals
Fish







Aquatic
Cold-blooded
Body covered with
wet and slimy scales
Streamline body for
easy movement
through water
Fins for balance and
to control movement
Gills for breathing
External fertilization
Amphibians



Cold-blooded
Moist, scaleless skin
Limbs present
– tetrapods


Larvae (tadpoles) use
gills for breathing;
adults use lungs
External fertilization
Reptiles





Cold-blooded
Body covered with
dry, hard scales
Live on land
Breathe with lungs
Internal fertilization;
lay shelled eggs
Birds






Warm-blooded
With feathers
With wings
Beak for feeding
Lungs for breathing
Internal fertilization;
lay shelled eggs
Mammals






Warm-blooded
Hairs on skin
Females have
mammary glands for
producing milk
Lungs for breathing
Diaphragm present
Internal fertilization;
embryos develop
inside mothers’ bodies
Plants


Eukaryotic
Most plants contains photosynthetic
pigments (e.g. chlorophyll) for
photosynthesis
– Autotrophic

Can be divided into two groups:
– Non-flowering plants
– Flowering plants
Non-flowering plants

4 groups:
– Algae
– Mosses
– Ferns
– Gymnosperms
Algae




Aquatic
Simple multicellular
plants
No root, stem or leaf
Contain photosynthetic
pigments (e.g.
chlorophyll) for
photosynthesis
Mosses


With simple leaves and stems
No root
– with rhizoids for anchorage and absorption
of water



No vascular tissues
Reproduce by spores
Found in damp area
Ferns



With true roots,
stems, leaves and
vascular tissues
Reproduce by
spores
Live in damp
places
Gymnosperms

Reproduction by
producing seeds
– Seeds develop in
cones, not enclosed
by fruits
 naked seeds

Needle-shaped
leaves to reduce
water loss
Angiosperms (Flowering plants)


With flowers for
reproduction
Seeds are
produced inside
the fruit (matured
ovary)
Two groups of flowering plants
Cotyledons
Dicotyledons
Monocotyledons
Two
One
Leaf venation Netted
Parallel
Root system
Fibrous root
system
Tap root system